1. Field of the Invention
The present invention relates generally to locking devices and more particularly to an improved anti-vandalism locking device which is particularly adaptable for use upon panic-type doors commonly employed within public buildings.
2. Description of the Prior Art
Many buildings, such as for example, large stores, schools, theaters and other public institutions which are frequented by the public in relatively large numbers are commonly equipped with double panic-type doors which are adapted to be opened by pushing downwardly upon horizontally disposed, waist-level crossbars or panic bars respectively mounted upon the inner surface of the doors, such bars in turn operating conventional door-latch mechanisms. Such doors are also provided with key-operated devices which can also operate the latch mechanisms and in this manner, the doors may be locked from the outside, however, the same may always nevertheless be operated from the inside as a result of the depression of the horizontally extending panic bars toward the interior door surfaces.
Panic-type doors of the aforenoted construction however, have in fact proven vulnerable to vandals and thieves who have apparently discovered the fact that the doors may be opened from the outside of the building and access thereby gained to the building by means of inserting a hooked wire through the narrow vertical opening defined between the double doors, so as to grasp the panic bar and upon pulling the same downwardly, the door latch mechanism may be unlocked in a manner similar to that which is normally employed when exiting from the building. As a result of such unauthorized entrance, institutions have recently been subjected to a substantial amount of vandalism and theft. A need therefore, exists to render such panic-type doors free from unauthorized intrusion in the manner discussed above.